Filter for tobacco smoke



Dec. 8, 1959 P. A. MULLER 2,916,039

FILTER FOR TOBACCO SMOKE Filed Jan. 22, 1957 2 Sheets-Sheet 1 Dec. 8,1959 UL 2,916,039

FILTER FOR TOBACCO SMOKE Filed Jan. 22, 1957 2 Sheets-Sheet 2 IN VENTOR. Pam A020 fifd lfll United States Patent FILTER FOR TOBACCO SMOKEPaul Adolf Miiller, Herrliberg, Switzerland Application January 22,1957, Serial No. 635,470

Claims priority, application Switzerland January 25, 1956 7 Claims. (Cl.131-208) The present invention relates to a filter cord or rod for theproduction of filter plugs for cigarettes, cigars, etc., and inparticular for the production of so-called multi-layer filters havingfilter sections or portions of different properties following oneanother in the smokes direction of flow.

Such double or multiple layer filters are already known and are as arule used when the actual filtering material-for instance cotton wool orelse powdery substances such as activated carbon-is unsuitable forforming the end of the filter mouthpiece. In such cases the free end ofthe filter plug is formed by a porous member which is readily permeableto smoke, somewhat absorbent and abuts inwardly against a filter sectionforming the absorbent filtering body. As successive filter sectionsconsist here of different materials, the mechanical manufacture of suchmulti-layer filter plugs naturally involves considerable difficulty andcalls for complicated equipment.

The present invention aims at eliminating these difficulties in theproduction of such filter plugs and relates to a method of producing afilter cord or rod capable of being worked into multilayer filter plugsfor tobacco goods, particularly cigarettes, which cord or rod hasunitary filter sections of different properties following each other inthe smokes direction of flow, characterized by the fact that the filtercord is produced from an at least a single layer, virtually endless,uniform web of material which can be folded in a transverse directionand has its material structure altered differently in successivetransverse zones, whereupon the web of material is gathered together ina transverse direction to form an endless cord or rod with sections ofdifferent structure or texture following each other in the longitudinaldirection.

The arrangement according to the invention for producing such a filtercord is characterized by a device, through which the strip of materialcontinuously passes and which is designed to achieve structuralalterations in narrow zones transverse to the webs direction of travelso that altered and unaltered transverse zones follow one another, andfurther characterized by means designed subsequently to gather said Webof material into an approximately round filter cord.

A filter cord produced in accordance with this method is characterizedby at least one web of material which is gathered together in atransverse direction and has transverse zones of different textures orstructures.

It should be pointed out that the multi-layer filter cord according tothe invention consists of a plurality of cord or rod sections whichfollow each other in the direction of flow or path of smoke and of whichadjacent sections have in each case a different structure. Furthermore,the filter cord may of course also be produced from one or severalsuperposed webs of material by gathering same transversely to thelongitudinal direction of the web and thus has in every cross-sectionalplane a plurality of layers arranged above and beside one another.

It is therefore one of the primary objects of the invention to providemeans affording ready adjustment in length of the less absorbent sectionand the more absorbent section of a filter plug for use in cigarettes.

It is another object of the invention to provide means conducive to avery effective filter structure in rod formation, which effectuates ahighly desirable elimination of smoke ingredients in cigarettes.

The above and other objects of the invention will become furtherapparent from the following detailed description, reference being madeto the accompanying drawings, showing preferred embodiments of theinvention.

A few typical embodiments of the invention will, by way of example, nowbe described in detail in conjunction with Figs. 1 to 18 of the attacheddrawing in which:

Figs. 1 and 2 are an upright and a horizontal projection respectively,both drawn partly in section, of a typical embodiment for an arrangementaccording to the invention, shown in diagrammatic reproduction;

Fig. 3 is a perspective representation of a filter Web according to theinvention;

Fig. 4 is a folding aid shown in cross-section;

Figs. 5, 6 and 7 are each cross-sections through examples of a filtercord which can be produced with the arrangement according to theinvention, shown in diagrammatic reproduction;

Figs. 8, 9 and 10 are each upright projections and sections throughvarious embodiments of deforming rollers;

Figs. 11 and 12 are each diagrammatic reproductions of two overlappingwebs of material;

Figs. 13 to 18 are various longitudinal sections through filter cordportions, designed to explain how the latter are worked into filterplugs.

The arrangement illustrated in Figs. 1 and 2 is, by way of example,intended for the production of an endless double filter cord from atwo-layer web of material. One web of material 1, forming the carrier,is unwound from the magazine roll 2 and passes through all the deformingmeans provided, while the second web of material 3, forming a fibrecoating, is not applied to the carrier web 1 via the laying roller 4until the structure of said carrier web has already been altered.

The web of material 1 consists here, by way of example, of an absorbentpaper web of given width which passes from the magazine roll 2 via theguide pulley 5 to the pair of rollers 6, 7 which represent in this casethe first deforming means. Said two rollers 6 and 7 have a plurality ofinterlocking stamping edges which extend annularly along theircircumference and are so designed that the paper web 1 is provided witha corresponding number of longitudinal grooves, although the width ofthe web is at least approximately preserved. This, of course, can onlybe achieved by simultaneously stretching the paper Web 1 in a transversedirection, i.e. in the direction of the rollers axes. Such a stretchingof the material results in a desirable structural alteration of thelatter, in that the paper fibres are pulled apart and, if the depth ofthe grooves is adequate, unconnected longitudinal cracks appear in theweb. Such crimping of the paper web in the longitudinal directionsubstantially increases the absorptive power of the paper, which is ofadvantage for the present purpose. The axial distance and the radialdimensions of the stamping grooves as well as their contours can, ofcourse, be selected as desired in order to obtain a finer or coarser, orelse a shallower or deeper longitudinal crimping of the paper web. Sucha longitudinally crimped paper web can be easily gathered togethertransversely to the direction of travel to form an endless cord. g

The rollers 6 and 7 are completely uniformly provided with stampinggrooves of the type described along their efiective axial extension. Itis of course also. possible to provide only certain annular zones of theroller surface with such stamping grooves=so that a paper web isproduced which has longitudinally crimped and non-crimped strips side byside. A

p 3 The paper web 1, which in the embodiment according to Figs. 1 and 2is longitudinally crimped'over its entire width, then passes to a pairof rollers 8 and 9, comprising a toothed roller 8 and a counter roller 9provided with corresponding depressions, which pair of rollers serve toperforate the paper web 1. In this case only certain sec- .torsofthe-roller-s circumference are provided with perforating teeth along theentire axial extension of the roller 8 so that. individual paralleltransverse zones of'the longitudinally crimped material web 1 areperforated on each occasion; that is to say, perforated andnon-perforated transverse zones follow each other in the direction oftravel. If desired, the two rollers 8, 9 can, of course, also be usedsimultaneously as toothed roller and counter roller so that some of theperforations are made from above and others from below. The perforatingrollers 8 or 9 are preferably sodesigned that material is not punchedout of the paper web, but only dislodged and the edges of the individualperforation holes are frayed, which increases the filtering effect ofsuch apaper web in the perforated sections.

The paper web 1, which is longitudinally crimped in a uniform manner andis perforated in sections, is covered beneath the roller 4 with a fibreweb 3, by way of example a fleece consisting of natural fibres such ascotton or cellulose, and the web of material which now has twolayers'passes beneath the pair of perforating rollers 10, 11 whichconstitute a further deforming means.

The toothed roller 10 is in this case designed in exactly the same wayas the toothed roller 8 and is rigidly coupled with the latter so thatthepaper web covered with a fibre web is perforated only in thosetransverse zones which have already been perforated in the pair ofrollers '8, 9. The toothed roller 10 perforates both the fibre web andthe paper web, the perforating teeth being preferably so designed thatat least certain fibres of the web are pushed through the holes in thepaper web underneath and project through the holes on the underside ofthe paper web. In this way not only is the fibre Web firmly fastened tothe paper web on the one hand, but on the other the adsorptive andabsorptive capacity of the two-layer material web is increased,particularly in the perforated sections of the web. Fig. 3 shows indiagrammatic reproduction the back of the two-layer web of materialafter it has left the pair of rollers 10, 11. It can be seen thattransverse zones 10 longitudinally corrugated in a uniform manner andperforated transverse zones 1d follow each other in the paper websdirection of travel. The paper web is extensively disintegrated andfrayed by the perforating operation and the longitudinal grooving, whichwas originally present, can hardly be recognized any more. The fibres ofthe fibre web 3 project through some of the perforation holes in theperforated sections of the web.

It is important that those longitudinal strips of the material web whichare perforated in the pair of rollers 10, 11 should if possible undergono further treatment influencing their structure and surface beforeentering the folding and gathering members, in order that. the frayedperforation edges and the fibre tufts should not be pressed against thesurface of the web. If, therefore, as in the present case, it is desiredthat the web of material be further deformed and passed through a pairof rollers 12, 13 before entering the inlet opening 14 of the foldingand gathering member 15, said deformation should be restricted to thetransverse zones 10 which have not been treated by the last pair ofrollers 10, 11., Accordingly, the knurling roller 12, which is rigidlycoupled to the pair of ro1lers,.10, 11,'has projecting irregularitiesonly insome annular zones and in those transverse zones of its surfacewhich cause a deformation of the sections of the web not perforated inthe pair of rollers 10, 11. The irregularities of the knurling-roller 12and suitable elastic sleeves on the counter roller 13 cause the materialstructure of the web to be compressed in the non-perforated sections 1c,while the previously perforated transverse zones 1d pass through thepair of rollers 12, 13 untouched. In this way the inlet opening 14 ofthe foldingand gathering member 15 receives a web of material consistingof parallel transverse zones of different structure following oneanother in the direction of travel, wherein a cord section of lowermechanical strength but increased absorptivity and filtering efficiencyis always adjacent to a section of higher mechanical strength and lowerswelling capacity.

If desired, the web of material, before entering the folding andgathering member 15, can be divided into two or more parallel partialwebs. Said division can be accomplished by suitably designed kniferollers. By way of example, the knurling roller 12 in Fig. 2 is equippedwith three knife-like cutting rings 12a which cut the two-layer web ofmaterial in the middle into four partial webs.

The web of material entering the folding and gathering member 15 must beas stable as possible in its structure. If, by way of example, the paperweb 1 has to be made pliable before entering the longitudinal crimpingand transverse stretching rollers 6, 7 in order to achieve an adequatedegree of deformability for the subsequent deformation, the paper webshould be stiffened by suitable aftertreatment at a suitable point ofthe arrangement in order to'ensure that the properties of the filtercord leaving the folding and gathering member 15 do not change evenafter a prolonged period of time. By way of example, it has provedsuitable in the case of some fairly hard kinds of paper to make thepaper web pliable by moistening it with water mist or hot aqueous steambefore it enters the rollers 6, 7. In this event, the web of material,the structure of which has been altered, is then submitted to a suitableaftertreatment on leaving the pair of rollers 8, 9, for which purpose asmooth electrically heated plate can be used across which the web ofmaterial passes. After this or some other appropriate aftertreatment theweb of material must in any case be in such a condition that no changesin its structure are to be feared after a prolonged period of time.

The folding and gathering member 15 consists here of a flat funnel 16which is continuously reduced in width from the inlet opening 14 andopens into a nozzleshaped channel 17, the cross-section of whichcorresponds to the desired size of the endless filter cord to beproduced. The dimensions of the inlet opening are adapted to the widthand thickness of the web of material in order to ensure that the latterwill enter smoothly. The lateral gathering operation effected by meansof the funnel interior, which becomes narrower in Width and larger inheight, can be facilitated in known manner by the incorporation offolding aids, of which an embodiment is shown by way of example in Fig.4. Here, for instance, the top 21 of the fiat funnel '16 is designed asa ribbed plate with longitudinal ribs 22, and the bottom 23 is so shapedthat a corrugated funnel channel 24 is produced, The amplitude of thesecorrugations, i.e. the height of the ribs 22, becomes larger in thedirection of travel, while at the same time the distance betweenadjacent ribs 2.2 narrows, thus resulting in a constantly increasingcorrugation and folding of the web of material passing through.

In order to overcome the friction which the web of material undergoesduring folding and gathering in the funnel 16, a feed device for thecord of material is provided in the following channel 17. Said deviceconsists here, by way of example, of two endless conveyorjbeltsZS and26, each of which is driven from driving "wheels27, 28 respectively, andpasses 'over guide pulleys 29, 30"and 5 31, 32, respectively, and formsat opposite points a part of the wall of the outlet channel 17. Thetravelling speed of the conveyor belts is adjusted to the speed of theweb of material entering the flat funnel 16, which speed is determinedby the deforming rollers.

On leaving the nozzle-shaped channel 17 of the folding and gatheringmember 15 the endless filter cord has the desired size. The material iscompressed by the gathering operation so that the filter cord tends toexpand in a radial direction. To prevent this, the filter cord, onleaving the folding and gathering member 15 passes through an apparatus33 in which it is provided in known manner with a sheath so thatpreservation of the cord size desired is ensured.

The resultant filter cord is diagrammatically reproduced incross-section in Figs. 5, 6 and 7. The sheath 34 contains in Fig. 5 amulti-folded crimped paper web 35, the gathering having been effectedwithout folding aids. Fig. 6 shows a web of material which has also beengathered without folding aids and consists of a carrier web 36 and afibre covering 37, i.e. a web of material such as is produced in thearrangement according to Figs. 1 and 2. Finally, Fig. 7 illustrates afilter cord which is produced by the regular folding of four partialwebs 38, 39, 40, 41, each of which has two layers.

The deforming means indicated in the embodiment according to Figs. 1 and2 represent of course only some of the many possible types of suchdeforming means. By way of example, more than one pair of rollers withinterlocking annular stamping edges can be arranged in series in orderto achieve an intensive longitudinal crimping. If, in this case, theaxial distance between adjacent stamping edges is reduced in eachsuccessive pair of rollers, the width of the web of material will alsobe reduced simultaneously with the step-by-step grooving, which isdesirable in the case of some materials that only tolerate slightstretching in a transverse direction. At least one roller of thesuccesive pairs of rollers of the various deforming means is alwaysdriven; if the diameter of the rollers being the same, the followingrollers are driven at a higher speed than the preceding ones, the web ofmaterial will be additionally stretched in its longitudinal direction.The same effect can be achieved with the pairs of rollers rotating atthe same speed if the diameter of the following pairs of rollers islarger.

Apart from the toothed rollers and knurled rollers indicated in Figs. 1and 2, it is also possible to use deforming rollers according to Fig. 8which consist in each case of a roller 42 or 43 acting as a top andbottom stamping die respectively, it being possible, as in the case ofthe rollers 8 and 10, for successive transverse strips to be providedwith irregularities of any desired shape. It is sufiicient merely tomake sure that there is an ade quate number of irregularities withineach such transverse zone in the direction of travel. Through-going oraxially subdivided transverse zones of such deforming rollers can also,as indicated in Fig. 9, be provided with oblique toothing 44. If it isdesired to change the machine over quickly to producing filter plugs ofdifferent efliciency, the rollers can be provided with exchangeablesurface zones for the irregularities required in each case. The grooveshapes of the longitudinally crimping rollers 6, 7 can also, asindicated in Fig. 10, be chosen differently. Finally, it is alsopossible to roughen certain surface zones of a web of material on one oron both sides by means of suitable brush-type rollers.

As can be seen from the description of the arrangement according toFigs. l and 2, as well as the alternative embodiments of same, it ispossible to produce virtually endless filter cords. As the webs ofmaterial to be handled are as a rule delivered from a magazine roll (2in Figs. 1 and 2), the arrangement has to be stopped and a full magazineroll inserted as soon as the previous one has been used up. Since,however, such an interruption is generally not desirable, means can beprovided which make it possible simply to pass from the end of one rollto the beginning of the next.

The construction of the endless filter cord produced in this way can beseen from Fig. 13. Inside the thin paper sheath 45 a cord section 10 isadjacent to a cord section 1d in every case. The desired cord profilecan be produced by wrapping the cord in the device 33 (Figs. 1 and 2),it being possible, if desired, to compress the cord in a radialdirection, ie to give it an elastic pre-stress. The endless filter cordaccording to Fig. 13 is then subdivided by means of suitable knowncutters, for instance rotating knives, into filter cord portions asshown in Fig. 14 which are suitable for subsequent handling on existingfilter plug machines and have a predetermined length between the lines46 and 47.

If, for instance, two-part filter plugs 11 mm. long are to be producedfrom filter Web sections each 5.5 mm. long and having a greater andlesser absorptive capacity, the filter sections 1c and 1d must each be11 mm. in length and the distance between the lines 46 and 47 mustaccordingly be 6X 11:66 mm. The endless cord is subdivided in such a waythat a half section of cord consisting of perforated material anddesignated 48d is present at either end, which material should abut thetobacco in the finished filter cigarette. The cord portion in Fig. 14comprises two other whole cord sections 1d and, in all, three whole cordsections 10.

The seven-part cord portion according to Fig. 14 is subdivided intothree double plugs in the present embodiment by halving the two wholecord sections 1d. One of said plugs is illustrated in Fig. 15 andconsists of a half cord section marked 49d at either end and a wholecord section 10 in the middle. Corresponding to the above-mentioneddimensions of the cord portion according to Fig. 14, such a double plughas a length of 22 mm.

If desired, the cord sections 10 and 1d can, of course, be of differentlengths, thus enabling, for instance, double plugs as shown in Fig. 16to be produced with the two half-length cord sections 50d at both endsand the short cord section 510 in the middle. These double plugs,however, can, if desired, have the same overall length as those in Fig.15. It is of course also possible to use cord sections 10, 1d which haveequal or different lengths and are of other dimensions, and, by way ofexample, to produce filter cord pontions which are similar to thoseshown in Fig. 14, have a length of 72, 78, 84, mm. and from which doubleplugs of 24, 26, 28, 30 mm. are made.

The filter cigarette can now be manufactured from such double plugs asshown in Fig. 15 with the aid of known machines commonly used in thecigarette industry. To this end, a double plug 52 is first arrangedbetween two tobacco-filled cigarettes 53 and then joined as shown inFig. 17. In the embodiment illustrated here, this is effected accordingto Fig. 18 by pressing the two cigarettes 53 against the double pluglocated between them and then wrapping said plug with a mouthpiece strip54 which projects beyond the double plug at both ends. Both cigarettes53 are simultaneously joined to the plugs 52 between them by means ofthe double-width mouthpiece strip 54 which has been moistened with glueon the inside. If the double plug is now cut along the line 55 and thecord section 1c thus halved, two filter cigarettes will result, eachconsisting of a tobacco-filled portion 53, a filter section 49d, whichabuts the tobacco, a half filter plug section 1c forming the suction endand a mouthpiece strip 54 surrounding the filter plug and the neck ofthe portion 53.

The present method thus enables an endless filter cord to be producedwhich, divided into separate sections, can be worked into two-partfilter plugs in existing filter plug machines.

Figs. 1 to 10 show that multi-layer filter plugs can brand of cigarette.

7 also be produced. by. this method. If the deforming rollers aresuitably designed, filter cords and, from them, double plugs can beproduced which, for instance, possess the configuration shown in Fig.16, but have in addition at each end of the cord section 510 a shortcord section of different structure and then correspondingly shortercord sections 50d. Furthermore, it may be pointed out that even beforethe pair of rollers 6, 7 suitable deforming means can be provided forthe purpose of producing successive transverse zones of differentstructure in the web of material 1. In place of the-deforming rollers itis of course also possible to use deforming tools o f-some other type,for instance upwards and downwards oscillating stamping or perforating"dies.

The single or'multiple web double or multi-layer filter cord produced bythe method described in'the foregoing 'consists'despite the cordsections of different material structure which follow each other in thelongitudinal directin0f the same material along its whole extent and notof different materials arranged one behind the other as'is the case withknown multi-layer filters. This is a great advantage not only withregard to thesim- .plicity of mechanical manufacture, but also onaccount filter cigarette is being smoked.

,Filter cords thus produced enable all requirements to be met bythe cordsections 1c forming the section end 'in respect of attractiveappearance, slight discoloration and absence of taste during smoking,specified invariable compression strength, etc., as the longitudinalcrimping and the width of the Web of material can be chosen accordingly.Without impairing these properties of the suction end in any way,however, the filtering cord section 1a can be fully adapted to varyingrequirements in respect of nicotine and tar elimination, resistance toflow, swelling capacity, absorptive capacity, etc. by fraying anddisintegrating the web material to a greater or lesser extent.

As Figs. and 16 show, the length of the less absorbent section and ofthe more absorbent'section inside the filter plug may be different.

This enables the filter plug to be adapted in a simple manner to theelimination effect desired which may vary according to the With thepresent method of production such an increase or reduction of theefficiency can be easily achieved by setting the sectors, provided withirregularities, or the deforming rollers, for instance the rollers-shownin Figs. 8 and 9, at a greater or lesser angle along the circumferenceof the roller.

The method described in the foregoing was used, by W way of example, ,toproduce a filter cord capable. of being worked into two-layer filtersand consisting of a smooth paper web which could not be simply folded ina transverse direction. The arrangement employedwas that according toFigs. '1 and 2, but without the second web 3, the roller 4 and the pairsof rollers 10, 11 or 12, 13; The paper Web was moistened before enteringthe pair of rollers 6, 7 and dried by passing over a hot plate afterleavingrthe rollers 8, 9. The rollers 6 and 7 were heatable. A filtercord was produced at a transit speed 'ofmore than one metre a second andworked directly into filter plugs in known machines. Such filter .plugs,on being opened, reveal a paper web with through-going longitudinallycrimped grooves and irregularly distributed crack-like perforations inthe longitudinal direction,

:as well as a transverse zone with aplurality of additional roundperforations. By arranging a .pair. of knurling "rollers, for instanceof the type shown in Fig. 8, between the longitudinally crimping rollers6, 7 the toothed. rollers 8, 9, it was possible to produce a'filter webin Section without round perforation:

' Percent Reduction of nicotine 6 Reduction of tar 11 Section with roundperforation:

Percent Reduction of nicotine 24 Reduction of tar 28 Various changes andmodifications may be made without departing from the spirit and scope ofthe present invention and it is intended that such obvious changes andmodifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent, is:

l. A filter cord which is capable of being divided into filter plugs fortobacco smoking articles comprising a first layer of filter paper havinglongitudinal grooves therein, said first layer having spaced portionsthereof perforated, and a second layer of fibrous material disposedagainst said first layer and having spaced perforated sections andhaving frayed edges of said perforated sections extending into andthrough said perforated portions of said first .layer securing saidsecond layer to'said first layer.

2. A filter cord which is capable of being divided into layer of filterpaper having longitudinal grooves therein, said first layer havingspaced portions thereof perforated, and a second layer of fibrousmaterial disposed against said first layer and having spaced perforatedsections provided with frayed edges at said perforated sectionsextending into and through said perforated portions of said first layersecuring said second layer to said first layer, said layers beinggathered together in a transverse direction to a substantiallycylindrical shape.

3. A filter cord which is capable of being divided into filter plugs fortobacco smoking articles comprising a first layer of filter paper havinglongitudinal grooves therein, said first layer being provided withspaced perforated portions, a second layer of fibrous material disposedagainst said first layer and provided with spaced perforated sectionsterminating in frayed edges extending into and through said perforatedportions of said-first layers being gathered together in a transversedirection to a substantially cylindrical shape, and a tubular sheathdisposed about said layers. a V

4. A filter for a tobacco smoking article comprising a first layer offilter paper, a second layer of fibrous material disposed againstsaidfirst layer, said second layer including fibers extending into andthrough said first layer thereby'securingsaid second layer to said firstlayer, said layers being gathered to a substantially cylindrical shape,and a tubular'sheath disposed about said layers.

5. A filter for-a tobacco smoking article comprising a first layerof'filter paper having longitudinal grooves therein together with spacedlongitudinal cracks, said first layer being provided with'spa'cedpetforatedportions, a second layer of fibrous material disposed againstsaid first layerv and provided with spaced perforated sections, theperforations of said sections being defined by frayed edges extendinginto-and through said perforated portions of said first layertherebysecuring said second layer to said first layer, said layers beingcompressed to a substantially cylindrical shape, and apapersheathdisposed thereabout holding said layersin' the cylindrical shape with anelastic pre-stress thereon.

6 A filter plug for a cigarette comprising a first layer of filter paperhaving distortions therein for rendering said first layer moreabsorbent, a second layer of fibrous material disposed against saidfirst layer, said second layer including fibers extending into and\through said first layer thereby securing said second layer to saidfirst layer, said layers being compressed to 'a substantiallycylindrical shape, and a tubular sheath disposed thereabout holding saidlayers in the cylindrical shape with an elastic pre-stress thereon.

7. A filter rod for the manufacture of double-filter plugs forcigarettes; comprising a plurality of successive filter sectionsincluding first sections and second sections, respectively, all of saidsections comprising fibrous web material gathered to assume rodformation, said first sections alternating with said second sections anddiffering in texture in regard to absorptive quality from that of saidsecond sections, all of said sections being of predetermined length andextending across said rod formation, the distance between two adjacentfirst sections being substantially equal to the distance betweencorresponding two adjacent second sections, said first sections beingprovided with substantially parallel corrugations extending inlengthwise direction of said fibrous Web material, said web materialbeing provided with perforations arranged a predetermined distance fromeach other.

References (Zited in the file of this patent UNITED STATES PATENTS2,164,702 Davidson July 4, 1939 2,202,839 Davidson June 4, 19402,666,005 Morehad Jan. 12, 1954 2,698,269 Sussenbach Dec. 28, 19542,718,255 Levin Sept. 20, 1955 2,743,763 Westerkamp May 1, 1956 FOREIGNPATENTS 741,416 Great Britain Dec. 7, 1955

